<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1,user-scalable=no">
</head>
<body>
<div class="content_body">
    
</div>
<script>
    let arr=[10,10,10,10];
    let result=arr.reduce(function (tmp, item, index) {
        return (tmp+item);
    });
    console.log(result*4);
</script>
</body>
</html>